Airbag device

ABSTRACT

The present invention provides an airbag device that is capable of restraining a rectification cloth that switches a vent hole to an opened or closed state so as not to be twisted, and that is capable of switching the vent hole from an opened state to a closed state, and further, switching to the opened state. At an initial stage at which an airbag main body inflates and expands, the vent hole  8  is arranged between the leg portions  5 , and when the airbag main body is in a predetermined internal pressure state, the vent hole is closed by means of the band-shaped portion  4 . If an occupant or the like comes into contact with the airbag main body, a tense state of each of the leg portions is released, the rectification cloth is established in a slackened state, and the vent hole  8  is established in an opened state.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is divisional application of U.S. patent application Ser. No.13/240,691 filed Sep. 22, 2011, which claims priority of Japanese PatentApplication No. 2010-211959, filed on Sep. 22, 2010 and Japanese PatentApplication No. 2010-266693, filed in Nov. 30, 2010, the disclosure ofthe prior applications are hereby incorporated in their entirety byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an airbag device having an airbag thatis capable of being inflated and expanded by means of a gas that issupplied from a gas generator such as an inflator if a collision of avehicle or the like occurs. In particular, the present invention relatesto an airbag device that is capable of preventing twisting of a tetherconfigured to open or close a vent hole; that is capable of makinginflation and expansion speedily while restraining gas evacuation fromthe airbag at an initial stage at which the airbag inflates and expandsto thereby set an inside of the airbag at a predetermined internalpressure; and that is capable of reliably making gas evacuation when anoccupant or the like comes into contact with the airbag. In addition,the present invention relates to an airbag that is mounted in a vehicle,and that is capable of making airbag expansion that is suitable foroccupant.

2. Description of the Related Art

Conventionally, in a vehicle such as an automobile, an airbag device hasbeen installed in order to protect occupant from an impact if a vehiclecollision occurs. A variety of models of airbag devices have beenpractically available to protect occupant at a rear passenger sheet orto protect pedestrian, or to protect occupant from an impact if acollision of a side face of a vehicle occurs or if a roll of a vehiclesideways occurs, as well as to protect a driver or an occupant at apassenger sheet. In addition, the shapes or the like of airbags areformed differently in accordance with an installation location or usage.

Many airbag devices are constructed to inflate and expand a baggy airbagby means of a high-pressure gas that is generated from a gas generatorif a vehicle collision occurs, to thereby absorb and alleviate an impactcaused by the collision or the like by means of the airbag. In this way,such airbags employ a construction for protecting occupant from animpact or the like.

Such airbag devices are constructed to inflate and expand an airbagmomentarily by means of a high-pressure gas that is ejected from a gasgenerator and then appropriately release the gas inside of the airbag ata stage of constraining occupant so as to be thereby able to adjust apressure inside the airbag and then effectively constrain occupant.

As a construction that appropriately releases the gas inside the airbag,there has been employed a construction that forms a vent hole for gasevacuation at an airbag main body. A variety of constructions of a gasevacuation portion via a vent hole has been conventionally proposed. Forexample, there has been proposed an airbag device for passenger seat,which is capable of restraining gas evacuation by increasing aventilation resistance from a vent hole at an initial stage of inflationand expansion of an airbag, and that is capable of fully opening thevent hole at a later stage of the inflation and expansion (refer toJapanese Unexamined Patent Application Publication No. 2002-193058), oralternatively, an airbag device for vehicle, which is capable ofeffectively protecting a head of occupant even in either case where theoccupant takes a seatbelt in a construction to open or close a vent holewith the use of a tether or not (refer to Japanese Unexamined PatentApplication Publication No. 2009-196551) or the like.

With reference to FIG. 6, the airbag device for passenger seat,described in Japanese Unexamined Patent Application Publication No.2002-193058, will be described as related art 1 of the presentinvention. As shown in FIG. 6, a part of a suspension cord main bodyportion 32 is pulled out from a gas evacuation opening 31 that is formedin an airbag 30 to the outside of the airbag 30 to thereby constitute aclosed portion 33. At an initial stage at which the airbag 30 performsinflation and expansion, a ventilation resistance of the gas evacuationopening 31 is increased by means of the suspension cord main bodyportion 32 to thereby restrain gas evacuation.

In addition, at a later stage at which the inflation and expansion hasbeen performed, the suspension cord main body portion 32 is completelypulled into the airbag 30 to be thereby able to set the gas evacuationopening 31 in a fully opened state. Then, a height dimension of theairbag 30 having performed inflation and expansion, i.e., a thickness ofthe airbag 30 receiving occupant is adapted to be able to be restrainedby means of a suspension 34 that is pulled into the airbag 30.

This airbag device for passenger seat is capable of restraining a gasevacuation flow rate of the gas that is evacuated from the gasevacuation opening 31 in the course of inflation and expansion of theairbag 30, and is also capable of effectively utilizing an inflation gasfor inflation and expansion of the airbag 30.

With reference to FIG. 7, the airbag device for vehicle, described inJapanese Unexamined Patent Application Publication 2009-196551, will bedescribed as related art 2. As shown in FIG. 7, a tether 42 is arrangedin an airbag 40 for passenger seat, and subsidiary vent holes 43 areformed at one pair of side potions 42A of the tether 42. At the forwardside of each of the side portions 42A, a redundant portion 42 configuredto expand by breakage of a tear seam 45 is formed. One pair of the sideportions 42 a is retained in a predetermined cable routing passagewayalong a guide 46, and the tether 42 is retained at an intermediateportion 42B so as to be disposed on a movement locus that a head ofoccupant who does not take a seatbelt traces.

When the airbag 40 for passenger seat has inflated and expanded, in acase where occupant has taken a seatbelt, an upper part of the bodyincluding the occupant's head is constrained by means of the seatbelt,and thus, the quantity of movement of the occupant's part to the forwardside of the vehicle is limited. Therefore, the quantity of theoccupant's part to get into the airbag 40 for passenger seat is reduced.

At this time, a compression force acting on the intermediate portion 42Bof the tether 42 that is arranged in the airbag 40 for passenger seatbecomes less than a predetermined value, failing to reach a breakageload of the tear seam 45 of the redundant portion 44. Thus, theredundant portion 44 is maintained as it is without being expanded, andin a side view, the subsidiary vent hole 41 is maintained in a state inwhich it is superimposed on a vent hole 41, i.e., in a state in whichthe vent hole 41 is opened. The gas in the airbag 40 for passenger seatis then continuously evacuated from the vent hole 41, so that aninternal pressure of the airbag 40 for passenger seat can beappropriately kept.

When the airbag 40 for passenger seat has inflated and expanded, in acase where occupant has failed to take a seatbelt, the seatbeltconfigured to constrain an upper part of the body including theoccupant's head from moving to the forward side of the vehicle has notbeen taken, and thus, the occupant's head moves to the forward side ofthe vehicle as it is. Therefore, the quantity of the occupant's headgetting into the airbag 40 for passenger seat increases, and acompression force (a tension force) that acts on the intermediateportion 42B of the tether 42 becomes a predetermined value or more. Thetear seam 45 having retained the redundant portion 44 then breaks.

Then, the redundant portion 44 expands, and one pair of side portions42A at the left and right of the tether 42 is pulled to the side of theintermediate portion 42B. As a result, the subsidiary vent hole 43 thatis formed in each of the side portions 42A moves to a position which isnot superimposed on the vent hole 41, and the vent hole 41 of the airbag40 for passenger seat is closed. In this manner, the internal pressureof the airbag 40 for passenger seat is maintained in a high state, andthe upper part including the occupant's head can be appropriatelyconstrained.

In the invention described in Japanese Unexamined Patent ApplicationPublication No. 2002-193058, at the initial stage of inflation andexpansion of the airbag 30, the ventilation resistance of the gasevacuation opening 31 is increased by means of a part of the suspensioncord main body portion 32 that is pulled out from the gas evacuationopening 31 to the outside of the airbag 30 to be thereby able torestrain gas evacuation. In addition, at the later stage of theinflation and expansion, the suspension cord main body portion 32 iscompletely pulled into the airbag 30 to be thereby able to establish thegas evacuation opening 31 in a fully opened state. Moreover, the heightdimension of the airbag 30 can be restrained by means of the suspensioncord main body portion 32 that is pulled into the airbag 30.

However, a gas is always evacuated from the gas evacuation opening 31,and a further modification is required to further efficiently utilizethe gas that is generated from the gas generator and then downsize thegas generator.

The invention described in Japanese Unexamined Patent ApplicationPublication No. 2009-196551 is constructed so as to adjust gasevacuation with the use of the tether 42 formed in a linear shape.However, in a case where occupant has failed to take a seatbelt, whenthe side portions 42A are established in a distorted state, it becomes asituation that the vent hole 41 cannot be closed by means of the sideportions 42A.

That is, each side portion 42A is arranged between one pair of sideportions 46, and if twisting occurs between one pair of the sideportions 46 or if twisting occurs at the intermediate portion 42B or thelike of the tether 42, such each side portion 42A is also distorted dueto the above twisting. Then, at a circumferential edge part of the venthole 41, a site which is not covered with each of the side portions 42Ais formed. If the internal pressure of the airbag 40 for passenger seatincreases, a gas evacuation flow rate of the gas from the site that isnot covered with each of the side portions 42A increases, an area of theside that is not covered with each of the side portions 42A increases,and the vent hole 41 is established in an opened state.

However, Japanese Unexamined Patent Application Publication No.2009-196551 described above fails to disclose or suggest a solution orconstruction for prevention of a problem with twisting of the sideportions 42A.

The present invention has been made to solve the conventional problemdescribed above, and it is an object of the present invention to providean airbag device, with a simple construction, that is capable ofrestraining a rectification cloth configured to switch a vent hole to anopened or closed state so as not to be distorted; that is capable ofperforming speedy inflation and expansion while restraining gasevacuation from an airbag at an initial stage at which the airbaginflates and expands; that is capable of reliably performing gasevacuation if occupant or the like comes into contact with the airbagpartway of expansion and inflation; that is capable of stopping gasevacuation and maintaining an internal pressure of the airbag in apredetermined internal pressure state when the internal pressure of theairbag has reached at the predetermined pressure; and that is capable ofreliably making gas evacuation if occupant or the like comes intocontact with an airbag that has reached a predetermined internalpressure.

In addition, in order to alleviate an impact to occupant in a case ofvehicle collision, a variety of airbags are known, and their mountinglocations also increase. A variety of airbags are applied to manyvehicles, including an airbag configured to expand forward of occupantstaking a driver seat and a passenger seat in order to cope withcollision from a front side or a side cushion-type airbag or acurtain-shaped airbag partially covering side portions of a vehicle inorder to cope with collision of another vehicle with a side face or rollof vehicle sideways.

With the spread of such airbags, their effectiveness is verified in avery large number of actuation cases (collision cases), whereas avariety of attempts are made as to a modification for providing aprotection that is further preferable as well.

As the related art according to the present invention, there exists anairbag that is inflated and expanded by means of a gas supplied from aninflator into a baggy bag main body, the airbag including: a variablevent hole in which a gas distribution state inside and outside of thebag main body is changed in accordance with an expansion state of thebag main body; and a distribution state change means for changing a gasdistribution state in the variable vent hole, wherein the bag main bodyis expanded in a stepwise manner in a plurality of directions, thedistribution state change means is established in an allowable stateallowing for gas distribution in an initial expansion direction at aninitial stage of inflation and expansion of the bag main body, and isconfigured to selectively set the allowable state and a restraint staterestraining gas distribution inside and outside of the bag main body viathe variable vent hole, at a subsequent stage of expansion that issubsequent to the initial stage of expansion, and that is in anexpansion direction different from the initial expansion state (forexample, refer to Japanese Unexamined Patent Application No.2005-14861).

In Japanese Unexamined Patent Application No. 2005-14861 that is therelated art, one linear base cloth valve is used to open or close a gasevacuation hole for evacuating a redundant gas for airbag inflation andexpansion suitable for protection of occupant.

However, in the linear base cloth valve, the base cloth valve is thinneddue to breakage or twisting of the base cloth valve at the time of themaximum inflation and expansion of an airbag, the gas evacuation hole isnot well closed, and there is a possibility that suitable airbagexpansion cannot be performed.

Therefore, there is a need to contrive a preferred folding method or ameans for smoothing movement of the base cloth valve, airbag researchand development or manufacturing stage becomes complicated, and therehas been a problem associated with a higher cost.

Accordingly, it is an object of the present invention to provide anairbag that is capable of stably and easily making suitable airbagexpansion that is a solution of the problem described above.

SUMMARY OF THE INVENTION

Object of the present invention is mainly characterized by an airbagdevice comprising an airbag that is inflated and expanded by means ofgas supplied from a gas generator to constrain a target to be protected,wherein

the airbag includes: an airbag main body having a vent hole for gasevacuation, a rectification cloth arranged at the airbag main body andconfigured to switch the vent hole from an opened state to a closedstate and further to the opened state; and a guide base cloth having anopening, being engaged with the airbag main body, and guiding slidemovement in a longitudinal direction of the rectification cloth, theopening being superimposed on the vent hole,

the rectification cloth having a band-shaped portion and leg portionsseparately extending in a V-shape, from a partway in a longitudinaldirection of the band-shaped portion, an end portion of therectification cloth is engaged with the airbag main body, each of endportions of the leg portions is engaged with the airbag main body sothat a partial portion of the rectification cloth can be protrudedthrough the vent hole to an outside of the airbag main body, between theairbag main body and the guide base cloth, the band-shaped portion isconfigured to have a horizontal width dimension enough to open or closethe vent hole or an opening of the guide base cloth,

the guide base cloth has a first guide passageway configured to guidethe band-shaped portion and one pair of second guide passageways, arespective one of which is configured to guide said each leg portion,the opening of the guide base cloth is formed in the first guidepassageway,

-   -   when the rectification cloth is in a state before inflation and        expansion of the airbag main body, the vent hole or the opening        of the guide base cloth is arranged between the leg portions of        the rectification cloth, when an internal pressure of the airbag        main body reaches a predetermined internal pressure after        inflation and expansion of the airbag main body, the vent hole        or the opening is closed by the band-shaped portion, and when        the airbag main portion constrains the target and the        rectification cloth slackens, the partial portion of the        rectification cloth is protruded from the vent hole to the        outside to make the vent hole in the opened state.

In addition, the present invention is mainly characterized by the airbagdevice, wherein a length dimension of the band-shaped portion from anend part of the band-shaped portion that is engaged with the airbag mainbody to a branch portion that is divided into the leg portions is formedof a length dimension that is equal to a length dimension from aposition at which the end part of the band-shaped portion in the airbagmain body is engaged to the branch portion of said one pair of secondguide passageways in the guide base cloth.

Further, the present invention is mainly characterized by the airbagdevice, wherein the vent hole is formed at a back face side of theairbag main body, the guide base cloth is engaged with the back faceside of the airbag main body, the end part of the band-shaped portion isengaged between a boundary region between the back face side of theairbag main body and an occupant side of the airbag main body and a siteat which the guide base cloth is engaged, and each of the end portionsof the leg portions is engaged with a site of an occupant constraintface in the airbag main body.

According to the present invention, a vent hole can be controlled froman opened state to a closed state by means of a rectification cloth, inaccordance with an internal pressure of an airbag main body, andfurther, when a target to be protected comes into contact with theairbag main body that is established in a predetermined internalpressure state, the rectification cloth is established in a slackedstate and then the vent hole can be controlled from the closed state tothe opened state. That is, at an initial stage of inflation andexpansion of the airbag main body, inflation and expansion of the airbagmain body can be performed while gas evacuation from the airbag mainbody is performed. When the internal pressure of the airbag main bodyreaches a predetermined internal pressure state, the vent hole is closedby means of the rectification cloth that is established in a tense stateand then the vent hole is established in a closed state, whereby theinternal pressure of the airbag main body can be maintained in apredetermined internal pressure state.

A rectification cloth can be made of: a band-shaped portion; and legportions that are divided in V-shape, from a partway in a longitudinaldirection of the band-shaped portion. A guide base cloth that is engagedwith an airbag main body, for guiding sliding movement of therectification cloth, is configured to have a first guide passageway toguide the band-shaped portion of the rectification cloth and a pair ofsecond guide passageways to respectively guide the leg portions that aredivided into two ways. An opening of the guide base cloth that issuperimposed on a vent hole is formed in the first guide passageway.

With such a construction, if a rectification cloth is moved in adirection in which a band-shaped portion is pulled out from a firstguide passageway and then an expandable redundant portion of theband-shaped potion is established in a slackened state, a vent hole canbe disposed so as to be opened between leg portions that are dividedinto two ways of the rectification cloth. In addition, if therectification cloth is moved in a direction in which each of the legportions is pulled out from a respective one of second guide passagewaysand then the redundant portion of the band-shaped portion is caused toenter the first guide passageway, a vent hole or an opening of a guidebase cloth can be closed by means of the band-shaped portion.

If the airbag main body performs inflation and expansion, therectification cloth to close the vent hole is established in a state inwhich the cloth is pulled in a horizontal direction by means of the legportions that are divided into two ways. In addition, the band-shapedportion is established in a state in which it is pulled in a verticaldirection by means of an end part of the rectification portion and endportions of the leg portions.

That is, a tensile force in the horizontal direction and a tensile forcein the vertical direction act on the rectification cloth at the sametime, the band-shaped portion can be maintained in an always openedstate without twisting of the rectification cloth. Then, the vent holecan be reliably closed by means of the band-shaped portion having apredetermined width.

When an occupant, for example, comes into contact with the airbag mainbody that has been maintained in a predetermined internal pressurestate, the tensile state of the rectification is loosened and then therectification cloth slackens, enabling the rectification cloth havingclosed the vent hole to move in a direction of opening the vent hole.The vent hole can be then established in an opened state again. At thistime, with an internal pressure rise in the airbag main body, a part ofthe rectification cloth protrudes from the vent hole to the outside, andthe vent hole can be established in an opened state.

The gas that is filled in the airbag main body is then evacuated fromthe opened vent hole to the outside, whereby a more preferred resistanceforce is imparted to an occupant or the like having come into contactwith the airbag main body, and the occupant can be softly constrained.

As a site at which the rectification cloth is to be arranged, therectification cloth can be arranged at the outside of the airbag mainbody or can be arranged inside of the airbag main body. Even in a casewhere the rectification cloth is arranged outside or inside of theairbag main body, at a stage at which the internal pressure of the airbag main body reaches a predetermined internal pressure state, the venthole can be established in an opened state by means of the leg portionsthat are divided into two ways of the rectification cloth.

At the stage at which the internal pressure of the airbag main bodyreaches a predetermined internal pressure state, the band-shaped portionis established in a state in which the vent hole is closed by means ofthe rectification cloth that is established in a tensile state. Inaddition, when an occupant or the like comes into contact with theairbag main body that is established in a predetermined internalpressure state, the tensile state of the rectification cloth isslackened due to contact of the occupant or the like, enabling therectification cloth having closed the vent hole to move in a directionof opening the vent hole, and the vent hole can be established in anopened state again.

If the rectification cloth having closed the vent hole partially openedthe vent hole, the gas in the airbag main body increases an outflow rateat which the gas flows out from the partially opened vent hole to theoutside, and an opened area can be further increased. Then, a part ofthe rectification cloth can be protruded from the vent hole or anopening of the guide base cloth to the outside, and the vent hole can beestablished in an opened state.

Incidentally, while in vehicle running or the like, a driver or anoccupant at a passenger seat or the like does not always keep anappropriate riding position or a riding posture, and body sizes or thelike are respectively different depending on occupants. For example, adriver sometimes drives in a state of extreme forward inclinationposture in which an upper part of the body is made proximal to thesteering wheel (this state is referred to as “Out of position”, and ishereinafter abbreviated as an OOP).

At an initial stage at which the airbag main body inflates and expands,in a case where an occupant established in the OOP state comes intocontact with the airbag main body, the vent hole at this time is notcompletely closed by means of the rectification cloth, and isestablished in a partially opened state by means of the leg portionsthat divided into two ways. Therefore, even if the internal pressure ofthe airbag main body is increased due to contact of the occupant, theopened state of the vent hole is maintained. Then, the occupant can bekept in a state in which a resistance force relative to the occupant isreduced.

Therefore, according to the present invention, in a state that iscapable of coping with the OOP state, when an occupant comes intocontact an airbag, the internal pressure rise of the airbag main bodycan be restrained. In addition, inflation and expansion of the airbagmain body advances in a state in which a load on the occupant cominginto contact with the airbag main body is low. Moreover, during a periodin which there is a high possibility that the occupant established inthe OOP state comes into contact with the airbag main body, i.e., fromthe start of inflation and expansion of the airbag main body to the endof the initial stage, the vent hole is not closed. Therefore, a state inwhich gas is evacuated from the airbag main body is kept, and a state inwhich the load on the occupant coming into contact with the airbag mainbody is low can be maintained.

After the elapse of a period of time in which there is a highpossibility that the occupant established in the OOP state comes intocontact with the airbag main body, i.e., after the elapse of the initialstage at which the airbag main body has started inflation and expansion,the rectification cloth is established in a tensile state by means ofinflation and expansion of the airbag cloth, and a current state istransferred to a state in which a vent hole is closed. That is,appropriate countermeasure can be taken presupposing that an occupant isin an appropriate riding state. Then, when the internal pressure of theairbag main body reaches a predetermined internal pressure state, thevent hole can be closed by means of the rectification cloth.

That is, the vent hole can be established in an opened state at theinitial stage at which the airbag main body has start inflation andexpansion, or alternatively, the vent hole can be established in a closestate when the internal pressure of the airbag main body reaches apredetermined internal pressure state without an occupant or the likecoming into contact with the airbag main body partway of inflation.

In addition, even when an occupant or the like comes into contact withthe airbag main body partway of inflation, the vent hole is maintainedin its opened state, so that a gas excavation flow rate of the gas thatis evacuated through the vent hole with an internal pressure rise of theairbag main body can be increased. Then, the occupant can be kept in astate in which a resistance force relative to the occupant is reduced.

Further, after the internal pressure of the airbag main body has reacheda predetermined internal pressure state, when an occupant or the likecomes into contact with the airbag main body, the tensile state of eachof the leg portions keeping the vent hole in a closed state is loosened,so that the vent hole can be established in a fully opened state, asdescribed above.

According to the present invention, a length dimension of a band-shapedportion before being branched into the leg portions can be formed to bea length dimension that is substantially equal to a length dimensionfrom a position at which an end part of the band-shaped portion in theairbag main body is engaged with a branch portion of one pair of secondguide passageways. With such a construction, a vent hole can be reliablyestablished in an opened state at the initial stage at which the airbagmain body starts inflation and expansion, or alternatively, the venthole can be reliably established in an opened state when the internalpressure of the airbag main body reaches a predetermined internalpressure state without an occupant or the like coming into contact withthe airbag main body partway of inflation.

According to the present invention, sites at which an end part of theband-shaped portion and end portions of the leg portions are engagedwith the airbag main body are respectively formed at their predeterminedsites, whereby when an occupant or the like comes into contact with theairbag main body that is established in a predetermined internalpressure state, contact of the occupant or the like with the airbag mainbody is sensitively reacted and then the tensile state of therectification cloth can be loosened. Then, the band-shaped portion ofthe rectification cloth having closed the vent hole is allowed to movein a direction of opening the vent hole, and the vent hole can beestablished in an opened state again between the leg portions.

Object of the present invention is directed to an airbag according toclaim 5, and is described as follows.

An airbag device including an airbag that is folded, and that isexpanded by means of an inflation gas that is supplied from an inflator,

wherein the airbag has a gas excavation hole and a pulling member thatis a base cloth valve configured to open or close the gas evacuationhole,

wherein the pulling member has: a first mount portion that is mounted onan occupant-side airbag portion when the gas evacuation hole is definedas a center; a second mount portion that is mounted on a vehicle-sideairbag portion when the evacuation hole is defined as a center or thatis mounted on a vehicle; and a closed portion that is disposed to beable to be superimposed on the gas evacuation hole;

wherein the pulling member that is the base cloth valve is moved to bepulled by means of relative spacing between the occupant-side airbagportion and the vehicle-side airbag portion, and the closed portion isformed so as to be at least partially superimposed on the gas evacuationhole or so as to move to a restrictive position, and

wherein the first mount portion is formed by a plurality of mountpieces, is mounted at a plurality of mount points at a occupant side,and is configured so that a distance between the plurality of mountportions is large relative to a dimension in an original shape of theplurality of mount pieces of the pulling member that is the base clothvalve.

The present invention that is capable of solving the problem describedabove is directed to an air bag according to claim 6, and is describedas follows.

An airbag in which the first mount portion and the second mount portionare respectively formed by a plurality of mount pieces, in addition tothe invention according to claim 5.

The airbag according to the present invention has the configuration asdescribed above, and thus, has advantageous effects described below.

(1) The airbag of the present invention is structured to open, close,and open a gas evacuation hole for evacuating a redundant gas in orderto achieve airbag inflation and expansion suitable for occupant, apulling member that is a base cloth valve is formed by a first mountportion and a second mount portion, whereby tension of the gasevacuation hole can be concentrated at a predetermined site, outflow ofthe gas from the gas evacuation hole can be restrained, and suitableairbag expansion can be stably performed.

(2) By providing a pulling protection member, the pulling member isprevented from floating at the time of airbag expansion, and gas outflowcan be restrained to achieve more suitable airbag expansion.

(3) The pulling member can be configured by linearly cutting a basecloth at the time of manufacture of an airbag, thus improving yields.

(4) A first mount portion and a second mount portion of the pullingmember are mounted in an airbag after these mount portions have beendivided into a plurality of ways (for example, after the first mountportion has been divided into two ways); and therefore, a two-wayportion of the pulling member can be mounted while being kept away froma suspension cord for preventing excessive inflation of the airbag, thesuspension cord being generally provided in the airbag.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of essential portions, showing an inside ofan airbag main body from an occupant constraint face side after breakinga part of the airbag main body (first embodiment);

FIG. 2 is a perspective view showing an inside of the airbag main bodyfrom a wind shield side (first embodiment);

FIG. 3( a) is a plan view of a vent hole and its periphery in the airbagmain body at an initial stage of inflation and expansion (firstembodiment);

FIG. 3 (b) is a sectional view of essential portions shown in FIG. 3 (a)(first embodiment);

FIG. 4( a) is a plan view of a vent hole and its periphery in the airbagmain body in a state in which an internal pressure of the airbag mainbody reaches a predetermined internal pressure state (first embodiment);

FIG. 4 (b) is a sectional view of essential portions shown in FIG. 4 (a)(first embodiment);

FIG. 5( a) is a plan view of a vent hole and its periphery in the airbagmain body, in a state in which a target to be protected comes intocontact with the airbag main body that is established in a predeterminedinternal pressure state (first embodiment);

FIG. 5( b) is a sectional view of essential portions shown in FIG. 5( a)(first embodiment);

FIG. 6 is a perspective view of essential portions of a vent hole andits periphery (related art 1);

FIG. 7 is a horizontal cross section of an airbag for passenger seat(related art 2);

FIG. 8 is a schematic perspective view showing a second embodiment of aconstruction of an airbag according to the present invention;

FIG. 9 is a schematic front view showing an example of a pulling memberthat is a base cloth valve after base cloth cutting in the airbagaccording to the present invention;

FIG. 10 is an explanatory view showing an advantageous effect of thepulling member that is a base cloth valve being a feature of the airbagaccording to the present invention;

FIG. 11 is an explanatory view showing an advantageous effect of apulling member according to the related art;

FIG. 12 is an imaginary view when seen from the inside of the airbag,the view showing a state in which the pulling member that is the basecloth valve being a feature in the airbag according to the presentinvention is mounted on the airbag;

FIGS. 13( a), 13(b) and 13(c) are explanatory views showing a statuschange at the time of inflation and expansion of the airbag according tothe present invention; and

FIG. 14 is an explanatory view showing an advantageous effect of apulling member of another example of the airbag according to the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will be specificallydescribed below with reference to the accompanying drawings. An airbagdevice according to the present invention will be described hereinafterby way of example of airbag main body formed in a baggy shape. Theairbag device according to the present invention is not limitative tothe construction in which the airbag main body is formed in a variety ofairbags such as a single baggy shape, and the present invention ispreferably applicable to a side air bag having a subsidiary air bagbody, a side curtain air bag, an airbag for rear seat, a front curtainairbag, or an outside airbag. Therefore, the present invention is notlimitative to the embodiments described hereinafter, and a variety ofmodification can be made.

First Embodiment

A construction of an airbag main body 10 according to the presentinvention will be described with reference to FIG. 1 to FIG. 5. Aninflator mount portion 13 in the airbag main body 10 is shown, althoughan inflator that is arranged at a back face side of the airbag main body10 is not shown.

As shown in FIG. 1, in the airbag main body 10, an outer circumferentialedge of a main panel 2 at a wind shield side and an outercircumferential edge of a main panel 1 at an occupant constraint faceside are superimposed on an ear portion 12, and the ear portion 12 issewn at a sewing portion 11. An inflator, although not shown, isconfigured to be mountable on an inflator mount portion 13 that isprovided on the main panel 2. On the main panel 2, a vent hole 8 isformed, and in the airbag main body 10, a rectification cloth 3configured to open or close the vent hole 8 is provided. The airbag mainbody 10 is constructed with the main panel 1 and the main panel 2.

The airbag main body 10 is made of a non-ventilation flexible material,and for example, is formed by sewing a nylon-based base cloth panel, aninside of which is rubber-coated, that is, by sewing the main panels 1and 2 in a baggy shape. While a disk-shaped construction is shown as aconstruction of the airbag main body 10, this construction is merelyprovided as an example, and another configuration can be employed aslong as it is required for an airbag. In addition, the rectificationcloth 3 is constructed with a band-shaped tether made of a material thatis similar to that for the main panels 1 and 2. The rectification cloth3 can also be constructed by employing another material as required.

Hereinafter, while a description will be given by employing a mountconstruction by sewing as a construction to mount the rectificationcloth 3 and the guide base cloth 6 on the airbag main body 10, thepresent invention is not limitative to the mount construction by sewing,and the rectification cloth 3 and the guide base cloth 6 can be mountedon the back main body 10 by employing another publicly known mountingmethod.

As shown in FIG. 1 and FIG. 2, a control mechanism for switching thevent hole 8 in an opened or closed state is made of: a guide base cloth6 forming an opening 6 b at a position that is superimposed on anopening of the vent hole 8; and a rectification cloth 3, a slidingdirection of which is restrained by means of the guide base cloth 6. Asize of the opening 6 b formed in the guide base cloth 6 can be formedas a size that is substantially equal to that of the opening of the venthole 3 or as a size that is approximate thereto.

The rectification cloth 3 is provided with: a band-shaped portion 4having a predetermined width; and one pair of leg portions 5 that arecontinuously divided into two ways at the band-shaped portion 4. An endpart 4 a of the band-shaped portion 4 is sewn at an ear portion 12, andan end portions 5 a of each of the leg portions 5 is sewn in an occupantconstraint face in the main panel 1 or at the periphery of the occupantconstraint face.

The guide base cloth 6 is configured in a shape that is provided with: afirst guide passageway 7 a configured to guide the band-shaped portion 4of the rectification cloth 3; and one pair of second guide passageways 7b respectively configured to guide one pair of leg portions 5, and inthe first guide passageway 7 a, an opening 6 b superimposed on anopening of a vent hole 8 is formed. The guide base cloth 6 is sewn onthe main panel 2 by means of a sewing portion 11 so that the first guidepassageway 7 a and each of the second guide passageways 7 b.

As a length dimension in the band-shaped portion 4 of the rectificationcloth 3, a length dimension from an end part 4 a of the band-shapedportion 4 to a two-way portion 5 b into which the leg portions 5 aredivided can be formed to be a length dimension that is substantiallyequal to a length dimension from a position at which the end part 4 a ofthe band-shaped portion 4 in the main panel 2 is engaged to a two-wayportion 6 a of the guide base cloth 6 that is engaged with the mainpanel 2.

By forming the above length dimension in this way, at an initial stageat which the airbag main body 10 starts inflation and expansion, asshown in FIGS. 3 (a) and 3 (b), a redundant portion on the side of theend part 4 a of the band-shaped portion 4 can be slackened, and thetwo-way portion 5 b of one pair of the leg portions 5 can be establishedin a state in which the two-way portion fails to reach the opening ofthe vent hole 8 or the opening 6 b of the guide base cloth 6. Inaddition, at a stage at which the airbag main body 10 inflates andexpands and then reaches a predetermined internal pressure state, asshown in FIGS. 4 (a) and 4 (b), the opening of the vent hole 8 or theopening 6 b of the guide base cloth 6 b can be closed by means of theband-shaped portion 4.

FIG. 3 (a), FIG. 4 (a), and FIG. 5 (a) each show a state in the airbagmain body 10 in a state in which the main panel 1 on the occupantconstraint face side is not shown. FIG. 3 (b), FIG. 4 (b), and FIG. 5(b) each show a longitudinal cross section of the airbag main body 10while the periphery of the vent hole 8 is enlarged, and a schematicallyenlarged view is employed to clarify the construction. In FIG. 3 (b),FIG. 4 (b), and FIG. 5 (b), a construction of a protrusion dimensionrestraining tether 9 shown in FIG. 1 is not shown.

In addition, a length dimension in one pair of leg portions 5 can beformed to be a length dimension such that the band-shaped portion 4 andone pair of leg portions 5 can be established in a tensile state at astage at which the airbag main body 10 inflates and expands and thenreaches a predetermined internal pressure state. At this time, in theband-shaped portion 4, a tensile force in a horizontal direction and atensile force in a vertical direction are caused to act at the same timeby means of one pair of leg portions 5, so that the opening of the venthole 8 or the opening 6 b of the guide base cloth 6 can be closedwithout twisting of the band-shaped portion 4.

As shown in FIG. 1, on the occupant constraint face in the main panel 1,a protrusion quantity is restrained by means of a plurality ofprotrusion dimension retaining tethers 9 so that a gap from an inflatormount portion 13 reaches a desired gap when the airbag main body 10inflates and expands. One end side of the protrusion dimension retainingtether 9 is mounted on a back face side of the occupant constraint face,and the other end side is mounted on the inflator mount portion 13.

Next, with reference to FIGS. 3 (a), 3 (b), 4 (a), 4 (b), 5 (a) and 5(b), a description will be given with respect to switching of the venthole 8 to be controlled by means of the rectification cloth 3 from anopened state to a closed state, and further, switching from the closedstate to the opened state. FIG. 3 shows an opened state of the vent hole8 in a period in which there is a high possibility that an occupantestablished in the OOP state comes into contact with the airbag mainbody 10, i.e., in a period from the start of inflation and expansion ofthe airbag main body 10 to the completion of the initial stage.

As shown in FIG. 3( a), the rectification cloth 3 that is sandwichedbetween the guide base cloth 6 and the airbag main body 10 at this timeis established in a state in which a redundant portion of theband-shaped portion 4 is slackened, the vent hole 8 is positionedbetween one pair of leg portions 5, and the vent hole 8 is establishedin an opened state. That is, the opening 6 b of the guide base cloth 6and the vent hole 8 each are established in an opened state. A part ofthe redundant portion of the band-shaped portion 4, which can beslackened, can also be inserted into the guide base cloth 6 after beingfolded in a zigzag manner.

Then, as indicated by the outline arrow in FIG. 3 (b), part of the gasin the airbag main body 10 can be evacuated to the outside of the airbagmain body 10 through the opening 6 b of the guide base cloth 6 and thevent hole 8.

With reference to FIG. 3 (a), a description will be given with respectto a state in which an occupant established in the OOP state comes intocontact with the airbag main body 10 during a period from the start ofinflation and expansion of the airbag main body 10 to the completion ofthe initial stage. Hereinafter, a description will be given by way ofexample of a construction in which the airbag main body 10 is arrangedin a steering wheel, although not shown. If a vehicle collision or thelike occurs, the airbag main body 10 of an airbag device, although notshown, starts inflation and expansion, and breaks a cover of the airbagdevice. Then, the airbag main body 10 that is arranged in the coverfurther performs inflation and expansion due to an inflation gas from agas generator such as an inflator.

At this time, if an occupant established in the OOP state comes intocontact with the airbag man body 10, the internal pressure of the airbagmain body 10 rises, whereas as shown in FIG. 3 (b), the leg portions 5are established in a slackened state; and therefore, the opening 6 b ofthe guide base cloth 6 or the vent hole 8 is not closed by means of therectification cloth 3. Accordingly, gas evacuation from the airbag mainbody 10 is continuously performed.

The occupant coming into contact with the airbag main body 10 is therebyreceived and constrained, so that the internal pressure of the airbagmain body 10 can be lowered at a desired pressure reducing state. Inthis way, the internal pressure of the airbag main body 10 can belowered at the desired pressure reducing state, so that the occupant canbe reliably kept and constrained.

The state shown in FIG. 4 (a) is shown as a state in which the internalpressure of the airbag main body 10 reaches a predetermined internalpressure after the completion of the initial stage from the start ofinflation and expansion of the airbag main body 10. In this state, thestate of the airbag main body 10 having inflated and expanded ismaintained for a predetermined period of time, so that gas evacuationfrom the vent hole 8 is prevented.

As shown in FIG. 4 (b), the end portion 5 a of each of the leg portions5 is engaged by means of sewing or the like, with the back face side onthe occupant constraint face in the main panel 1. With thisconstruction, after the initial stage of inflation and expansion hascompleted, if the airbag main body 10 reaches a desired inflated state,the leg portions 5 are pulled by means of the main panel 1 and then theleg portions 5 are established in a tense state. The band-shaped portion4 is pulled by means of the leg portions 5 that are established in thetense state, and the two-way portion 5 b of the leg portions 5 moves toa position that is distant from the vent hole 8.

Then, the band-shaped portion 4 is pulled in the first guide passageway7 a, and the vent hole 8 or the opening 6 b of the guide base cloth 6 isclosed. At this time, as indicated by the outline arrow in FIG. 4 (b),gas evacuation from the vent hole 8 is prevented.

When the leg portions 5 are established in a tense state, theband-shaped portion 4 is also pulled by means of the ear portion 12between the main panel 1 and the main panel 2. However, as a lengthdimension of the band-shaped portion 4, a length dimension from the endpart 4 a of the band-shaped portion 4 to the two-way portion 5 b isformed to be a length dimension that is substantially equal to a lengthdimension of the main panel 2 from the ear portion 12 to the two-wayportion 6 a of the guide base cloth 6, whereby the band-shaped portion 4can be pulled in the first guide passageway 7 a by means of the legportions 5 that are established in the tense state.

Moreover, the tensile force in the horizontal direction acts on each ofthe leg portions 5, so that the tensile force in the vertical directionand the tensile force in the horizontal direction act on the band-shapedportion 4 at the same time, making it possible to prevent twisting ofthe band-shaped portion 4. Therefore, the rectification cloth 3configured to close the vent hole 8 or the opening 6 b of the guide basecloth 6 can reliably close the vent hole 8 or the opening 6 b of theguide base cloth 5 without forming a gap relative to the vent hole 8 orthe opening 6 b of the guide base cloth 6.

In addition, the end portion 5 a of each of the leg portions 5 ismounted on the back face side of the occupant constraint face in themain panel 1, so that when an occupant comes into contact with theoccupant constraint face, recession of the occupant constraint face tothe inside of the airbag main body 10 can be efficiently caused to workat the same time as such contact, and the tense state of each of the legportions 5 can be released.

In place of providing the protrusion dimension restraining tether 9shown in FIG. 1, or alternatively, as an assistance of the protrusiondimension restraining tether 9, a length dimension leading up to theoccupant constraint face 10 in the airbag main body 10 can also beformed so as to be restrained by means of the respective leg potions 5that are established in a tense state.

FIGS. 5 (a) and 5 (b) shows a state in which a head 14 of an occupant (adummy doll) comes into contact with the airbag main body 10 when theairbag main body 10 inflates and expands and then enters the state shownin FIGS. 4 (a) and 4 (b). After the elapse of the initial stage ofinflation and expansion in the airbag main body 10, when the airbag mainbody 10 inflates and expands in a state in which the vent hole 8 isclosed, if the head 14 comes into contact with the airbag main body 10,the occupant constraint face in the main panel 1 of the airbag main body10 is recessed, and the internal pressure of the airbag main body 10rises to a predetermined internal pressure or more.

Then, the occupant constraint face is recessed, whereby the tense stateof each of the leg portions 5 is released, the rectification cloth 3 isestablished in a slackened state, and a part of the rectification cloth3 having closed the vent hole 8 or the opening 6 b of the guide basecloth 6 protrudes from the vent hole 8 to the outside. Moreover, theprotrusion quantity from the vent hole 8 in the rectification cloth 3 tothe outside is controlled in accordance with the internal pressure ofthe airbag main body 10. In this manner, the occupant can be reliablyconstrained by means of the airbag main body 10.

As described above, the present invention is capable of reliablypreventing the band-shaped portion 4 in the rectification cloth 3 frombeing established in a twisted state, and is also capable of switchingthe vent hole 8 from an opened state to a closed state, and further,switching it from the closed state to the opened state again. Moreover,when the vent hole is established in the closed state, the gas that isgenerated from an inflator that is a gas generator can be efficientlyutilized for inflation and expansion of the airbag main body 10, so thata small-sized inflator can be employed as such an inflator.

Hereinbefore, while a construction in which a rectification cloth 3 isprovided in a vent hole 8 of an external air release type has beendescribed as a construction of the present invention, the presentinvention is not limitative to such a construction in which arectification cloth is provided in a vent hole of an external airrelease type. The present invention is also applicable to a constructionin which a rectification cloth is provided in a vent hole of an internalair release type. That is, in a construction in which a pressureadjusting bag that is a second chamber is provided outside of a firstchamber, a rectification cloth can be provided in a vent hole of aninternal air release type, the vent hole being provided to communicatebetween the first chamber and the second chamber.

Second Embodiment

Hereinafter, a second embodiment of the present invention will bedescribed as another embodiment.

First, the second embodiment of the present invention will be generallydescribed. In the linear base cloth valve of the related art, there is apossibility that the base cloth valve becomes thin due to folding ordistortion of the base cloth valve at the time of the maximum inflationand expansion of an airbag, and contrivance is required to stably andeasily make an opening or closing operation of a gas excavation hole.Therefore, the airbag according to the present invention, as shown inFIG. 12, has: a gas excavation hole 3A; and a pulling member 4Aconfigured to open or close the gas evacuation hole 3A, and has a firstmount portion 7A of an occupant-side airbag portion 2A; a second mountportion 6A of a vehicle-side airbag portion 1A; and a closed portionthat is disposed to be able to be superimposed on the gas evacuationhole 3A. The pulling member 4A is moved to be pulled by means ofrelative spacing between the occupant-side airbag portion 2A and thevehicle-side airbag portion 1A, the closed portion is configured so asto be partially superimposed on the gas evacuation hole 3A or so as tomove to a restrictive position. The first mount portion 7A isconstructed with a plurality of mount pieces, and is mounted at aplurality of mount points on the occupant side, and a distance betweenthe pluralities of mount portions becomes greater than a dimension inoriginal shape of the plurality of mount pieces of the pulling member4A.

Next, the second embodiment of the present invention, which has beengenerally described above, will be described in detail with reference tothe accompanying drawings. FIG. 8 is a schematic perspective viewshowing a construction of an airbag according to the present invention.According to the airbag of the present invention, the gas excavationhole 3A for evacuating the gas that is contained in the airbag to theoutside is provided in an inflation body of an opposite occupant-sidemain panel 1A of the airbag; the second mount portion 6A that is alinear portion of the pulling member 4A is sewn on the oppositeoccupants-side main panel 1A; and the first mount portion 7A that is theother end part of the pulling member 4A is formed in a two-way shape,and is configured to be sewn from the opposite occupant-side main panel1A to the occupant-side main panel 2A. FIG. 9 shows the pulling member4A after base cloth cutting. The pulling member 4A to be used in thepresent invention can be formed in a two-way shape by linearly cuttingthe first mount portion 7A of a linear base cloth; and therefore, thepulling member can be produced at a cost similar to that of the relatedart, regardless of the fact that there is attained an effect that ismore advantageous than that of a pulling member 4A formed in a linearshape, of the related art, and the yields is also improved. FIG. 10shows an advantageous effect of the pulling member 4A in the airbag ofthe present invention. The pulling member 4A of the present inventionhas: the second mount portion 6A that is a linear site; and the secondmount portion 7A that is a site divided into two ways. If a respectiveone of these mount potions is pulled at the time of airbag expansion, atension concentrates on a portion that is superimposed on the gasevacuation hole 3A for evacuating the gas that is contained in theairbag of the pulling member 4A to the outside, gas evacuation from theairbag is restrained, and airbag expansion suitable for occupant can beprovided.

FIG. 11 shows the pulling member 4A′ of the related art. Unlike that ofthe present invention, this pulling member is not divided into two ways;and therefore, a tension concentrates on the entire top and bottom fromthe center of the left and right. Accordingly, there may occur a case inwhich the pulling member is folded or distorted in the horizontaldirection or the gas evacuation hole 3A cannot be sufficiently closed,and there is also a need to set a position of the base cloth valve or anacting point of pulling in folding of the airbag, or alternatively, tocarry out an adjustment work of a guide structure in which smoothsliding can be obtained.

FIG. 12 is an imaginary view when seen from an inside of an airbag, theview showing a state in which a pulling member is mounted on the airbag.The pulling member 4A is provided at a position that is superimposed onthe gas evacuation hole 3A for evacuating the gas that is contained inthe airbag to the outside, and on the pulling member 4A, a pullingprotection member 5A is provided. This pulling protection member 5Aserves to help smooth sliding of the pulling member 4A, and has anadvantageous effect of preventing floating of the pulling member 4A atthe time of airbag expansion.

Next, an expansion status change of the airbag according to the presentinvention will be described with reference to FIGS. 13 (a), 13 (b) and13 (c). FIG. 13 (a) shows a state immediately after airbag expansion.This airbag is on the way of expansion, and the first mount portion 7Athat is a two-way portion of the pulling member 4A opens, whereby thegas evacuation hole 3A of the opposite occupant-side main panel 1A andthe pulling member 4A are not superimposed on each other; and therefore,the gas evacuation hole 3A is established in an opened state. FIG. 13(b) shows a state in which the airbag inflates and expands at themaximum, and shows a state in which the pulling member 4A is pulled, alinear portion that is not a two-way portion is superimposed on the gasevacuation hole 3A, and the gas evacuation hole 3A is closed. FIG. 13(b) shows a state in which: an occupant comes into contact with theairbag; the occupant compresses the airbag; the pulling member 4A issuperimposed on the gas evacuation hole 3A; in that state the pullingmember 4A is pushed out from the gas evacuation hole 3A to the outsideof the airbag by means of a movement caused by airbag compression; andtherefore, the gas evacuation hole 3A is opened. Namely, an impact isapplied; a change of the gas evacuation hole 3A from a time immediatelyafter the start of airbag expansion to a time of the completion ofairbag expansion is made in sequential order of open-close-open; when anoccupant comes into contact with the airbag, an internal pressure of theairbag is established at the maximum; and a movement of the occupant tothe airbag side is supported and then the impact is absorbed. Afterthat, the internal pressure of the airbag is lowered so as to reduce aresistance force of airbag expansion to the occupant, and airbagexpansion suitable for occupant is provided.

Another Embodiment

Here, another embodiment of the present invention will be described.FIG. 14 shows another embodiment of the pulling member 4A. A two-wayportion that is provided in the first mount portion 7A is also providedin the second mount portion 6A that is on the opposite occupant-sidemain panel side as well as on the side of the occupant-side main panel2A, and a force can be concentrated on a more limitative location bymeans of tension concentration from four directional ways. Although notshown in the figure, on the first mount portion 7A and the second mountportion 6A, a pulling member 4A that is divided into multiple ways aswell as into two ways can be employed.

INDUSTRIAL APPLICABILITY

A technical idea of the present invention can also be applied to aconstruction of another airbag. In addition, the present invention isalso applicable to an airbag in a variety of modes and/or use locations,which is available for use in all kinds of vehicles.

1.-4. (canceled)
 5. An airbag device including an airbag that is folded,and that is expanded by means of an inflation gas that is supplied froman inflator, wherein the airbag has a gas excavation hole and a pullingmember that is a base cloth valve configured to open or close the gasevacuation hole, the pulling member has: a first mount portion that ismounted on an occupant-side airbag portion when the gas evacuation holeis defined as a center; a second mount portion that is mounted on avehicle-side airbag portion when the evacuation hole is defined as acenter or that is mounted on a vehicle; and a closed portion that isdisposed to be able to be superimposed on the gas evacuation hole; thepulling member that is the base cloth valve is moved to be pulled bymeans of relative spacing between the occupant-side airbag portion andthe vehicle-side airbag portion, and the closed portion is formed so asto be at least partially superimposed on the gas evacuation hole or soas to move to a restrictive position, and the first mount portion isformed by a plurality of mount pieces, is mounted at a plurality ofmount points at an occupant side, and is configured so that a distancebetween the plurality of mount portions is large relative to a dimensionin an original shape of the plurality of mount pieces of the pullingmember that is the base cloth valve.
 6. The airbag device according toclaim 5, wherein the first mount portion and the second mount portionare respectively formed by a plurality of mount pieces.